1. Field of the Invention
The present invention relates to a technique of controlling a substrate processing apparatus having an inspection part built therein for performing prescribed inspections on a semiconductor substrate, a glass substrate for a liquid crystal display, a glass substrate for a photomask or a substrate for an optical disk (hereinafter simply referred to as “substrate”).
2. Description of the Background Art
A product such as a semiconductor device or a liquid crystal display is manufactured by performing a series of processing such as cleaning, resist coating, exposure, development, etching, formation of an interlayer dielectric film, thermal processing, dicing and the like on the aforementioned substrate.
In order to maintain the quality of such a semiconductor product, it is important to inspect the substrate for confirming the quality thereof after the aforementioned processing. In general, therefore, the aforementioned series of processing is performed on a pilot substrate as preprocessing for inspecting the quality of the pilot substrate.
FIG. 16 schematically illustrates the structures of a conventional substrate processing apparatus 7 and a control system therefor. As shown in FIG. 16, the substrate processing apparatus 7 and an exposure apparatus 8 connected to the substrate processing apparatus 7 are connected to a controller 6, for performing a series of processing (coating, exposure and development) on substrates under control of the controller 6. An inspection apparatus 9 is arranged outside the substrate processing apparatus 7.
A preprocessed pilot substrate is stored in a dedicated carrier of the substrate processing apparatus 7. An operator carries the carrier to the inspection apparatus 9 for performing inspection processing therein.
When inspection results as to the pilot substrate are not satisfactory for quality requirements, the operator changes the processing condition of each processing part of the substrate processing apparatus 7 or the exposure apparatus 8, and performs the series of processing on a new pilot substrate again. The operator carries the preprocessed pilot substrate to the inspection apparatus 9 for performing inspection processing. The operator repeats such processing thereby optimizing the processing condition of each processing part. The operator ends the preprocessing when the processing condition is optimized, for starting actual substrate processing steps (the actual substrate processing steps are hereinafter referred to as “actual processing”).
Thus, the operator performs quality inspections by preprocessing for starting actual processing when the quality satisfies the requirements, whereby high-quality substrates can be produced from the start time of the actual processing.
However, the operator must manually change the processing condition of each processing part in response to the inspection results of the preprocessing through extremely complicated processing. The operator must determine the contents of the processing condition to be changed from the inspection results for changing the processing condition of each processing part on the basis of the results of the determination.
Due to the structure of the inspection apparatus 9 provided outside the substrate processing apparatus 7, the operator must repeatedly carry the carrier as the case may be, leading to a heavy burden on the operator.
Thus, there are some problems as to inspection processing of the pilot substrate. While resist film thickness measurement is performed on a product lot in order to maintain the quality of semiconductor products, film thickness measurement on a bare wafer is performed as an apparatus check of the substrate processing apparatus 7 itself independently of the film thickness measurement on the product lot.
The film thickness measurement on the bare wafer is performed when the lot is changed or at the time of a daily check. The term “bare wafer” indicates a substrate formed with no pattern. While a part formed with no pattern must be selected for performing film thickness measurement as to a substrate already formed with a pattern, more correct film thickness measurement can be performed by measuring the film thickness in a state coating the bare wafer with resist.
As shown in FIG. 16, the substrate processing apparatus 7 executes a series of processing (coating and development) on substrates under control of the controller 6. The inspection apparatus 9 is arranged outside the substrate processing apparatus 7.
The dedicated carrier of the substrate processing apparatus 7 stores the bare wafer subjected to coating of resist in a coating processing unit (not shown) comprised in the substrate processing apparatus 7. The operator carries the carrier to the inspection apparatus 9, which in turn performs film thickness measurement.
When film thickness measurement results as to the bare wafer are not satisfactory for quality requirements, the operator changes the processing condition of the coating processing unit or a thermal processing unit (not shown) of the substrate processing apparatus 7, and performs resist coating processing on a new bare wafer again. The operator carries the bare wafer coated with the resist to the inspection apparatus 9 for performing film thickness measurement again. The operator repeats such processing thereby optimizing the processing condition of the coating processing unit. The operator ends the film thickness measurement when the processing condition is optimized.
However, the operator must manually change the processing condition of the coating processing unit or the thermal processing unit in response to the results of the film thickness measurement through extremely complicated processing. The operator must determine the contents of the processing condition to be changed from the measurement results for changing the processing condition of each unit on the basis of the results of the determination. In particular, the film thickness measurement with the bare wafer is performed every day as a daily check, and hence it follows that the overall processing efficiency is reduced when this operation is complicated.
Similarly to the inspection processing on the pilot substrate, the operator must repeatedly carry the carrier every time the film thickness measurement is performed due to the structure of the inspection apparatus 9 arranged outside the substrate processing apparatus 7, to result in a heavy burden of the operator.